Heretofore, plasma generating apparatus which generate reaction active sites by a plasma have been widely used for the processing of various materials, such as surface processing, thin-film deposition, and etching. For example, a plasma generating apparatus is used to deposit a film of a diamond-like carbon (DLC) on the surface of a substrate. The plasma generating apparatus creates a plasma state by ionizing a hydrocarbon gas, such as methane or acetylene, filled into a vacuum chamber, and uses the resulting reaction active species, such as radicals and ions, to deposit DLC films.
In the prior art, a technique is proposed that reduces the apparatus cost by making provisions so that power is supplied from a single power supply apparatus via a relay to a plurality of plasma generating apparatus provided one for each of a plurality of vacuum chambers or to a plurality of electrodes provided in a single vacuum chamber (for example, refer to Japanese Unexamined Patent Publication Nos. H10-340798, H11-40395, and 2003-129234).
For example, in the manufacturing process for manufacturing products in large quantities, it is preferable to be able to reduce the time required to process the products in order to increase productivity. It is therefore desirable to make provisions in such process steps as the film deposition using a plasma generating apparatus so that films can be deposited on the surfaces of a plurality of workpieces in a parallel and concurrent fashion.
However, the techniques disclosed in Japanese Unexamined Patent Publication Nos. H10-340798 and H11-40395 are intended so that, while performing processing using a plasma in one of the plurality of vacuum chambers, the transportation of workpieces, etc., can be carried out in the other vacuum chambers, and power from the power supply is supplied to one of the plurality of vacuum chambers via a relay. Accordingly, with these techniques, it is not possible to generate the plasma in the plurality of vacuum chambers simultaneously.
On the other hand, in the case of the technique disclosed in Japanese Unexamined Patent Publication No. 2003-129234, a plurality of pulse distribution supply means, provided one for each sputter evaporation source, are connected in parallel to a DC power supply, and each pulse distribution supply means includes a capacitor capable of storing power supplied from the power supply. According to this technique, by turning on a switch device incorporated in each pulse distribution supply means, a glow discharge can be generated between the negative electrode connected to the pulse distribution supply means and the positive electrode connected to the DC power supply.
Further, according to this technique, the switches are provided one for each sputter evaporation source and, by operating the switches to open and close at different timings under the control of a switch signal from a control mechanism, pulse-like power is supplied sequentially in a time-division fashion to the respective sputter evaporation sources. However, since this technique requires the provision of the control mechanism for adjusting the timing to supply power to the respective sputter evaporation sources, the apparatus configuration is complex.